Toilet Box
by Dr. Blind
Summary: Jace gets a nasty surprise when he takes Alec a box of his stuff to Magnus's apartment. Lemon. AlecXMagnus.
1. Toilet Box

**Toilet Box**

Jace had been in a lot of awkward situations over the years, but none even came close to the time he saw Alec and Magnus having sex.

It started like this. Jace was helping Alec move from the Institute into Magnus's apartment and noticed that he'd forgotten a box in the back of his closet. The box, of course, was filled with bathroom things so Jace thought it was of the utmost importance to bring it over for them. Of course he called first, and found that Alec was out watching Magnus get his nails done. So he decided to just bring it over.

Only he was held up in the subway station and missed his train and then got off at the wrong stop to help a kid find his mom and ended up at Magnus and Alec's an hour and a half later than he thought he'd be. He took the box to the bathroom and ended up draining the lizard while he was in there. Meanwhile, he heard a door slam open and a loud muffled noise in the other room. They were fighting, which was awkward. Jace made sure to flush and wash his hands extra loud, then opened the bathroom door violently so they knew he was there.

A snappy quip about arguing lover's died immediately on his tongue as he walked down the hall into the living room. Alec was pushed up against the wall, shirt long gone and pants unbuckled, his wrists pinned above his head by one of Magnus's hands. The warlock was biting and licking Alec's collarbone, causing him to make strange, erotic noises. Jace froze. He didn't know what to do. Awkward situation. AWKWARD SITUATION. Alec would be mortified. He would decide to avoid Jace instead of delaing with any discomfort.

Jace stepped backwards. He would wait until they were done. He would pretend he was constipated and enraptured with one of the magazines coated in make-up sitting on Magnus's counter. The floorboard behind him creaked loudly and Magnus stopped. Both boys looked around, but Jace was hidden from their view.

"Chairman," Alec gasped. "Don't stop."

AHHHH! screamed Jace internally. Alec was not allowed to gasp! He was not allowed to say things like "don't stop!" Jace put his hands over his eyes and looked at the floor. He had to be calm. He could only be sneaky if he was calm.

"Nggh. Magnus..." moaned Alec.

SHUT UP SHUT UP SHUT UP, thought Jace.

And yet a tiny voice in the back of Jace's mind was curious. Not to see gay sex starring his parabatai and the Sparkle King, of course. Jace was terrible at coming up with new fourplay things. Who better to learn from than an eight-hundred year old?

Jace looked. Alec's head was thrown back and his eyes were fluttering. His chest was shuddering. Though Jace couldn't see it, he knew Magnus had his hand down the front of Alec's pants. Well that certainly wasn't a helpful tip.

Magnus let go of Alec's hands for just a moment and Alec quickly grabbed his shoulders and crashed their lips together. Jace had seen them make out only twice before and both of those times had nothing on the hot, sloppy, carefree way they were going at it then. Alec pushed Magnus right down onto the floor and forced his shirt over his head before quickly undoing his pants. Whoa, Jace certainly wasn't going to learn anything from that. He put his hands back over his eyes and tried to think of London.

"Alec... Don't be a tease," Magnus panted.

"But that's half the fun," Alec said huskily. There was a loud thud and Alec began laughing hysterically.

"You think that's funny?" Magnus snickered.

"I think everything you do is funny."

Jace peeked his eyes open to see what was so funny. Magnus was straddling Alec, bent over and kissing his throat again. Alec was facing Jace, his eyes shut, biting his lip and smiling. Magnus suddenly ground their hips together and the smile disappeared. His eyes flew open halfway and he made a low cracking sound before grinding back on Magnus. The warlock hissed in a breath and leaned back. "Is that a threat, Lightwood?"

Alec propped himself up on his elbows and smiled innocently at Magnus for a moment before leaning forward and dragging his bottom lip from where his naval should have been to his collarbone. Magnus let out a choked breath and Alec wrapped his arms around his torso before rocking up onto his feet and then diving back onto his boyfriend so that he was on top again, in between Magnus's legs. The warlock lifted one knee and hitched the other around Alec's thigh.

Jace's face was pure red. He closed his eyes again. There was something so wrong about watching Alec and Magnus. It wasn't like looking in on just sex. It was looking in on a private moment between two people who really loved each other. Jace tried to take another step backwards, being lighter this time, when he heard Magnus whimper. The sound was so absurd that Jace had to open his eyes and see what caused it, at which point he witnessed his parabatai lick his boyfriend's cock for what was hopefully the last time.

Jace slapped his hand to his mouth so that he wouldn't shout anything and tried to force his eyes shut, but it was like watching a car crash. Magnus was so... big. Jace knew that there was a time and a place for penis envy and that was not the time nor the place. Luckily Alec moved and managed to block out what he was doing with his shoulder, but Jace could still hear Magnus panting and Alec working away. He could still see his head rise and fall and Magnus's fingers knotted in his hair. Magnus's eyes were half lidded and rolling. He kept chanting Alec's name, louder and faster until he suddenly stopped and raised his hand to bite his knuckle.

"Alec honey, you h-have to stop." Alec didn't stop and Magnus started pushing at his shoulder's. "A-Alec, please. I'm gonna c-cum."

Ah, Jace had been in that same awkward position before. Well, not that exact position. The thought made his stomach turn and he tried once again to look away. But Jace couldn't stop and Magnus couldn't stop and Alec wouldn't stop. Magnu's back arched and his voice cracked painfully as he moaned and orgasmed. Jace kept his eyes fixed on Magnus's face, terrified of what he'd see if he looked at Alec's. A minute later Alec was back to kissing Magnus. It was different than before. There was something hungry in the way Alec held Magnus.

The warlock's pants were pushed down around his ankle's in a swift feat of Herculean skill. Alec nudged his legs apart wider then sat up to tug his baggy cargo pants low enough to get the job done. The Lord was merciful and Jace saw nothing of Alec's bits, but the story was different for Magnus, who was smirking with a glint in his eye. "For me? You shouldn't have."

"Oh, shut up," Alec laughed, and then dived on Magnus once more. There was a moment of kissing with only one hand and a quick shot of blue lightning and suddenly Magnus and Alec were huffing and groaning again. "I love you so much," Alec kept repeating. "You're so perfect."

Magnus was nodding and gasping and repeating Alec's name. "Don't... stop... ever..."

Jace covered his eyes again but the image was seared in the back of his head. Magnus's arms around Alec's neck. The top of Alec's ass rising and sinking, the way Magnus's raised knees were shaking. His skin felt cold and hot at the same time. Jesus, what was he doing?

"MAGNUS SHIT FUCK NGGGH!" Alec suddenly shouted. It was followed by a loud, long groan. Second's later Magnus's voice cracked again. The apartment was filled with heavy breathing. Minutes later it was replaced with a chuckle and a "Sorry," from Magnus.

Floorboards creaked and a belt jingled. Jace realized what was happening a moment too late. Jace opened his eyes just as Alec came into view of him. For just a second his parabatai had the mused hair and sated face that comes with really good sex. Jace's eyes immediately went to the jizz spattered over his stomach and onto his chest.

Alec's eyes went real wide and he turned completely white before he shrieked like a girl and fainted. The shadowhunter dropped like a stone, out cold.

Magnus sat up and scooted over so he could see what happened, then raised an eyebrow and shook his head. "Oh," he said, "yeah, Alec's gonna need his body soap."

At which point Jace ran from the apartment, never to speak of that day again.

**END**


	2. Next Day

**Next Day**

Jace did not want to face Alec. There was no way he would be able to look at him ever again. He was seriously contemplating moving to South America and becoming a travelling egg salesman when Alec walked into the sitting room and sat down in the chair opposite Jace. Red was creeping over his face and Jace could almost hear how hard his heart was pounding. Jace decided to play it cool. He looked up from his book, intending to smile and say hello.

He saw a hickey on Alec's neck, remembered the sound of Magnus moaning and Alec panting. His face turned green, then red, and he looked back down at his book.

"Jace..." Alec started, and then stopped abruptly. There was an awkward pause and then Alec tried again. "Jace, I know what you think you saw- "

"Oh no, I don't think anything." He shook his head, still looking at his book. "I think nothing of anything. I don't know what you're talking about. So maybe you should stop. Talking. No talking."

Alec took a deep breath. "We weren't doing what you think we were doing."

Jace couldn't help but snort. "Then what were you doing?"

"He was teaching me how to dance?"

Jace looked up from his book and finally met Alec's eyes. They were puffy, like he'd been crying or hadn't slept in a couple days. Maybe both. "Alec, really. Don't worry about it. It never happened."

"Jace, I- "

"No, really. You're two consenting adults. I should have given you your privacy." Jace looked back down at his book. "Besides, it's not like I didn't already know you two had sex. I just never thought I'd witness it in progress."

"We don't do that!" Alec cried in vain.

"Yes, Alec. Yes you do." He resettled himself on the couch, feeling a little bit like he'd pulling a heavy weight off his chest. "You do, and with great joy."

A cushion immediately hit him in the side of the head with such force that his ear rang. "Oh, shut up," Alec grumbled, his face red. Silence returned and Alec seethed. Jace continued reading, ignoring the thoughts swirling around his parabatai. "How..." he started, then stopped. "How much did you see?"

"More than I needed to in a million-billion-kajillion years."

"Jace..."

He slammed his book shut and met Alec's eyes dead on. "Well, do you want me to lie? Say I came out right when we met in the hall? Because I was standing there for a hell of a lot longer. It happened, Alec. I _saw_. Beginning to end. And honestly, it's haunting me wherever I go."

Something happened then that Jace had never imagined in a million years. Alec burst into tears and hid his face in his shirt, like a turtle receeding into its shell. From inside his cotton cacoon he ranted, "We got into a fight and on the way home. And I was mad and he was mad and the apartment was supposed to be empty and then he pushed me and I didn't know what to do because I didn't want to fight, so I pushed him against the wall and kissed him but he thought it meant I wanted sex, but I just wanted to eat nachos, so I tried not to, but you don't understand how convincing he is! He's like a... like a..."

"A witch?"

"He's like a witch! An evil, gorgeous, mindcontrolling witch with magical sex powers and I'm so fucking sorry."

Jace shook his head. "It doesn't matter, Alec. Really. I don't care."

"Really?"

He nodded. "Really. Consider it forgotten."

"Thanks, Jace."

Alec relaxed for the first time in days, letting his eyes drift shut. Jace almost let him sleep. He almost let Alec get away on that one. After a few minutes of silence, Jace gently closed his book and stood up. He crept to the door and looked back at Alec's gentle sleeping face. "You know," he said, a grin playing on his lips, "Isabelle and I had a bet. I won it."

Alec peeked one eye open, putting his feet up on the table. "Oh yeah?" he asked, voice heavy with sleep. "What was that?"

"She said you were a top. I swore you were a bottom. Weird."

And then Jace disappeared down the hallway, leaving Alec with his head in his hands and sleep miles away.


End file.
